Question: Khan.scratchpad.disable(); Nadia sells magazine subscriptions and earns $$10$ for every new subscriber she signs up. Nadia also earns a $$21$ weekly bonus regardless of how many magazine subscriptions she sells. If Nadia wants to earn at least $$53$ this week, what is the minimum number of subscriptions she needs to sell?
Solution: To solve this, let's set up an expression to show how much money Nadia will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Nadia wants to make at least $$53$ this week, we can turn this into an inequality. Amount earned this week $\geq $53$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $53$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $10 + $21 \geq $53$ $ x \cdot $10 \geq $53 - $21 $ $ x \cdot $10 \geq $32 $ $x \geq \dfrac{32}{10} \approx 3.20$ Since Nadia cannot sell parts of subscriptions, we round $3.20$ up to $4$ Nadia must sell at least 4 subscriptions this week.